Static gassing-out method for determining the volumetric oxygen mass transfer coefficient (k L a) in the fermentor system.

Static gassing-out method for determining the volumetric oxygen mass transfer coefficient (k L a) in the fermentor system.

Source publication
Article
Full-text available
Scale-up criterion of constant oxygen mass transfer coefficient(kLa) was applied for the production of itaconic acid(IA) in a 50L pilot-scale fermentor by the fungal cells of Aspergillus terreus. Various operating conditions were examined to collect as many kLa data as possible by adjusting stirring speed and aeration rate in both 5L and 50L fermen...

Context in source publication

Context 1
... determining the volumetric oxygen mass transfer coefficient (k L a) in the 5 L and 50 L fermentor systems, a static gassing-out method was used [8]. Oxygen was stripped from the liquid medium by purging with inert nitrogen gas. Time-course saturation of DO was then monitored as the air supply and stirring conditions were resumed (Fig. 1). The liquid balance of DO during this short time period can be expressed as ...

Similar publications

Article
Full-text available
The effects of temperature, agitation and aeration on glycoprotein GP-1 production by Streptomyces kanasenisi ZX01 in bench-scale fermentors were systematically investigated. The maximum final GP-1 production was achieved at an agitation speed of 200 rpm, aeration rate of 2.0 vvm and temperature of 30 °C. By using a dynamic gassing out method, the...

Citations

... There are several scale-up strategies; one efficient strategy is applying the scale-up criterion as the volumetric power input (P/VL), mixing time, impeller tip speed or constant volumetric mass transfer coefficient (k L a) in different size fermenters [21][22][23]. In the case of aerobic fermentation, maintaining constant oxygen transfer or k L a is a good choice [16]. ...
... k L a is a standard parameter for the characterization of mass transport by correlating the mass transfer rate with the concentration change [24]; this is the most important parameter for the design and operation of mixing/sparging [25]. As supplying adequate oxygen (gas-liquid mass transport) is a significant factor in aerobic cultures, maintaining a similar k L a has been frequently employed as the basis in the scaling-up process; besides that, the scale-up basis with the k L a criterion is commonly used in around of 30% of the fermentation industry [23,26,27]. The aim of this work was to demonstrate an efficient use of the k L a criterion in the scale-up process through three different sizes of bioreactor systems for the production of PRP by Hib. ...
... The linear profile of k L a obtained using the 1.5 L bioreactor was similar to the one obtained by Averkina et al. [34] under a stirrer range of 50-300 rpm. Therefore, there is a direct influence of agitation on gas; it is dispersed, caused by the impeller with a varying efficiency for breaking bubbles and produces the increase in the gas liquid interface area and residence time into the medium culture [26,33,35], while the k L a profile obtained in 15 L and 80 L was similar to that reported by Shin et al. [23] under evaluation of a different stirrer and aeration rate. ...
Article
Full-text available
Polyribosyl-ribitol-phosphate (PRP) from Haemophilus influenzae type b (Hib) is an active immunizing molecule used in the production of the vaccine against H. influenzae, and industrial production could contribute to satisfying a world demand especially in developing countries. In this sense, the aim of this study was to establish a scale-up process using the constant oxygen mass transfer coefficient (kLa) such as the criterion for production of PRP in three different sizes of bioreactor systems. Three different kLa values (24, 52 and 80 h−1) were evaluated in which the biological influence in a 1.5 L bioreactor and 52 h−1 was selected to scale-up the production process until a 75 L pilot-scale bioreactor was achieved. Finally, the fed-batch phase was started under a dissolved oxygen concentration (pO2) at 30% of the saturation in the 75 L bioreactor to avoid oxygen limitation; the performance of production presented high efficiency (9.0 g/L DCW-dry cell weight and 1.4 g/L PRP) in comparison with previous scale-up studies. The yields, productivity and kinetic behavior were similar in the three-size bioreactor systems in the batch mode indicating that kLa is possible to use for PRP production at large scales. This process operated under two stages and successfully produced DCW and PRP in the pilot scale and could be beneficial for future bioprocess operations that may lead to higher production and less operative cost.
... A higher IA titre was achieved for the later conditions (48.5 g⋅L − 1 , compared with 30.5 g⋅L − 1 ), which was linked to the lower extent of damage to mycelia at a fixed agitation of 300 rpm, explaining why most of the studies (cited in Table 3) using A. terreus have used agitation varying from 300 to 400 rpm. Shin et al. [84], in 2013, scaled-up IA production from 1.5 to 50 L, keeping the kLa at 0.02 s − 1 and reported the highest yield until thus far in an STR (0.72 g IA /g glucose ). This value is remarkably high and near the maximum theoretical yield, productivities, and titres for different A. terreus strains (productivities: 0.32-0.8 ...
Article
Full-text available
The discovery of itaconic acid as a product of citric acid pyrolytic distillation in 1837 opened the possibility of using it as a polymer building block. Itaconic acid, featuring two carboxylic acids and an unsaturated group, can potentially be used as a building block in several chemical syntheses, with a particular emphasis on polymer manufacture. The elucidation of biochemical pathways originating from itaconic acid, first in Aspergillus terreus and, recently, in several species of the Ustilago genus, has intensified and diversified research focused on microbe-based itaconic acid production, including at an industrial scale. These efforts include the engineering of naturally producing species/strains along with the exploration of other species that do not naturally produce itaconic acid but may offer potential benefits. The use of renewable wastes or sugar-enriched residues as substrates to produce itaconic acid, from a circular bioeconomy perspective, is another important aspect of the advancements in microbial itaconic acid production. This review provides an overview of the achievements as well as the challenges concerning the engineering of the producing strains/species, substrate selection, optimisation of bioreactor operation, and downstream itaconic acid purification methods.
... A plot of ln (1 2 C i /C*) against time can be used to estimate the k L a, while the final concentration can be used to estimate the maximum oxygen concentration and to set the probe at 100%. This technique is classical (Atkinson & Mavituna, 1992;Shin et al., 2013), but still important because (1) it accommodates specificities of the fermentation conditions, from bioreactor geometry and stirring rate to temperature and pressure, to culture media composition; and (2) because if k L a can be replicated in scaling-up, then the OTR can possibly be replicated too, leading to the desired, similar physiological conditions in both scales. ...
... These methods involve the determination of impeller speed and aeration rate, which rely on empirical correlations, and keeping one or more parameters constant (Badino et al., 2001;García-Ochoa & Gó mez, 2009;Mahdinia et al., 2019;Marques et al., 2010;Vasconcelos et al., 2000). The gas surface velocity, specific gas flow rate, or gas flow number are the criteria adopted to estimate the aeration rate (Shin et al., 2013;Shukla et al., 2001). ...
... The volumetric oxygen transfer coefficient (k L a) reflects the bioreactor's ability to transfer oxygen to microbial cultures. Oxygen transport is an essential parameter to be considered in the scale-up of aerobic processes, since it is needed in microbial metabolism (Shin et al., 2013) especially in processes that demand large amounts of oxygen, such as the production of antibiotics , itaconic acid (Magalhaes et al., 2019), citric acid (Mores et al., 2021), and yeast and bacterial fermentation for different biomolecules' production (Junker, 2004). Besides, oxygen can also act as a final electron receptor in the reoxidation of electron-carrying molecules in bioprocesses (García-Ochoa & Gó mez, 2009;Liu, 2017). ...
Chapter
The definition of bioprocesses’ parameters generally occurs at bench scale. However, the reproduction of these processes’ conditions at pilot and/or industrial scale is certainly a challenge. These conditions are for example aeration, which involves critical aspects such as dissolved oxygen and oxygen uptake rate, and agitation, which promotes shear stress and needs high energy consumption. It is important not to lose process efficiency and productivity, which impact on bioeconomy of biotechnological processes. So, some well-known scale-up strategies can be employed, combined or individually, to maintain bioprocesses’ performance. These strategies consider geometric similarity aspects of bioreactors, agitation and aeration conditions, and some rheological aspects of the fluid that must be considered and maintained at the new scale. Some operational conditions have a great influence on cell growth and on the biosynthesis of different biomolecules and should be reproduced at higher scales. Accordingly, one or more operating factors can be maintained constant during scale-up and some procedures can be employed, for example, to determine the power consumption of large-scale bioreactors or determine aeration conditions in an aerobic culture. Stirred tank reactors will be employed as models for scale-up. However, the scale-up of other bioreactors models such as bubble column reactors and solid-state bioreactors will also be described.
... The aeration of the growing microorganism must be carried out equally in the entire work volume of the bioreactor and needs to be enough for its maintenance. Another benefit of a good system of aeration and agitation is to diminish the size of mycelial aggregates, making the access to cells easier to oxygen [28][29][30][31]. The online bioreactor used provides a good system of aeration and agitation. ...
... The aeration of the growing microorganism must be carried out equally in the entire work volume of the bioreactor and needs to be enough for its maintenance. Another benefit of a good system of aeration and agitation is to diminish the size of mycelial aggregates, making the access to cells easier to oxygen [28][29][30][31]. The online bioreactor used provides a good system of aeration and agitation. ...
Chapter
The global organic acid market is expected to reach USD 36.86 Billion in 2026. This study aimed to produce citric, itaconic, and gluconic acids by using a biotechnological process in a lightly stirred bioreactor with fungus from the genus Aspergillus spp. These fermentations processes provided good yields, 22.6%, 99.9%, and 24.8% (48 h) for citric, gluconic, and itaconic acids, respectively.
... Similar to the findings with citric acid fermentation [6], lowering the concentration of inorganic phosphate alleviated the inhibitory effect of Mn 2+ on itaconic acid production [58]. Interestingly, however, there are also reports on itaconic acid fermentations with high yields which do not attempt to remove metal ions [59,60]. This issue therefore needs further investigation. ...
Article
Full-text available
Organic acid accumulation is probably the best-known example of primary metabolic overflow. Both bacteria and fungi are capable of producing various organic acids in large amounts under certain conditions, but in terms of productivity-and consequently, of commercial importance-fungal platforms are unparalleled. For high product yield, chemical composition of the growth medium is crucial in providing the necessary conditions, of which the concentrations of four of the first-row transition metal elements, manganese (Mn2+), iron (Fe2+), copper (Cu2+) and zinc (Zn2+) stand out. In this paper we critically review the biological roles of these ions, the possible biochemical and physiological consequences of their influence on the accumulation of the most important mono-, di- and tricarboxylic as well as sugar acids by fungi, and the metal ion-related aspects of submerged organic acid fermentations, including the necessary instrumental analytics. Since producing conditions are associated with a cell physiology that differs strongly to what is observed under “standard” growth conditions, here we consider papers and patents only in which organic acid accumulation levels achieved at least 60% of the theoretical maximum yield, and the actual trace metal ion concentrations were verified.
... By subsequent transportation outside the cell, IA can be recovered from the broth by technologies such as membrane filtration and electrodialysis [12][13][14][15]. Although A. terreus has been proven as the most promising candidate for IA production, the actual bioprocess performance is highly-dependent on the environmental settings, in terms of substrate concentration, pH, temperature, media composition with respect to N-sources as well as the presence/absence of certain minerals, dissolved oxygen levels, stirring rate, etc. [16][17][18][19]. On that matter, to track how efficiently the biosynthesis proceeds under given bioreactor operating conditions, the most essential information can be acquired from the fermentation kinetics with special interest on substrate consumption, IA (as product) formation and biomass growth. ...
Article
Full-text available
In this work, itaconic acid (IA) was produced biotechnologically by Aspergillus terreus fungal strain from glucose. The performance of the batch fermentation was kinetically assessed and the maximal IA production potential, maximal production rate and lag-phase time were determined as 28.1 g/L, 3.83 g/L day and 1.52 days, respectively. In addition, the bioprocess was evaluated based on the most frequently used parameters, in particular IA titer (26.3 g/L), yield (0.22 g/g substrate) and productivity (0.1 g/L h), which were comparable to the already published literature. Furthermore, an on-line monitoring system was installed to the fermenter in order to measure the CO2 content of the bioreactor of-gas. Actually, it was indicated by the results that the CO2 production could have a linear-like relationship with the quantity of fungal biomass. Hence, the data collected in such a way may have the potential to establish an alternative methodology for the monitoring of biomass growth in the course of the biological transformation taking place.
... By controlling the pH at 3.4 after the itaconate initiating phase, product titers up to 160 g L −1 could be achieved [2]. Further productivity could be increased by media optimization and pHshift experiment to 1.15 g L −1 h −1 [16] and the highest reported yield with 0.72 g ITA g −1 GLC was reached by optimizing oxygen transfer [17]. Following submerged fermentation with A. terreus, the itaconic acid is typically purified by repeated crystallization in industrial settings [18]. ...
Article
Full-text available
Background: Ustilago cynodontis ranks among the relatively unknown itaconate production organisms. In comparison to the well-known and established organisms like Aspergillus terreus and Ustilago maydis, genetic engineering and first optimizations for itaconate production were only recently developed for U. cynodontis, enabling metabolic and morphological engineering of this acid-tolerant organism for efficient itaconate production. These engineered strains were so far mostly characterized in small scale shaken cultures. Results: In pH-controlled fed-batch experiments an optimum pH of 3.6 could be determined for itaconate production in the morphology-engineered U. cynodontis Δfuz7. With U. cynodontis ∆fuz7r ∆cyp3r PetefmttA Pria1ria1, optimized for itaconate production through the deletion of an itaconate oxidase and overexpression of rate-limiting production steps, titers up to 82.9 ± 0.8 g L-1 were reached in a high-density pulsed fed-batch fermentation at this pH. The use of a constant glucose feed controlled by in-line glucose analysis increased the yield in the production phase to 0.61 gITA gGLC-1, which is 84% of the maximum theoretical pathway yield. Productivity could be improved to a maximum of 1.44 g L-1 h-1 and cell recycling was achieved by repeated-batch application. Conclusions: Here, we characterize engineered U. cynodontis strains in controlled bioreactors and optimize the fermentation process for itaconate production. The results obtained are discussed in a biotechnological context and show the great potential of U. cynodontis as an itaconate producing host.
... In various reports, it was found that the efficiency of the process-in terms of the technologically most important IA yield and productivitycould be affected by the conditions provided in the fermenter unit. Actually, the variables that have been confirmed to take strong influence on bioreactor performance during IA production cover the quality of the medium and type of substrate, temperature, pH, aeration and stirring (Mondala 2015;Hevekerl et al. 2014;Karaffa et al. 2015;Kolláth et al. 2019;Molnár et al. 2018;Shin et al. 2013). ...
... Aeration and mixing intensity are crucial factors for aerobic bioprocess optimization (Garcia-Ochoa and Gomez 2009). As the production of IA is obligatory aerobic, it requires the maintenance of sufficient oxygen supply in the whole working volume of the bioreactor, influenced by the oxygen mass transfer conditions (Shin et al. 2013). For instance, Molnár et al. (2018) proved recently that the dissolved oxygen concentration as high as 30% of saturation level notably determined the fermentation profile with A. terreus, particularly in terms of IA rate and yield. ...
... As in the aerobic bioreactor unit, the factor that takes both aeration and stirring conditions into account is the so-called K L a (oxygen mass transfer coefficient) (Garcia-Ochoa and Gomez 2009), the next study in our research sequence ought to deal with the examination of K L a in assisting IA production. For instance, Shin et al. (2013) documented the increment of K L a in response to more vigorous mixing (from 100 to 300 rpm) and larger air loading (0.5-1.5 L/L min) for pilot-scale IA fermenter with A. terreus. Nevertheless, it is to stress that simultaneous setting of aeration and mixing for favorable K L a mustn't threaten the growth of A. terreus since the appearance of extreme shearing forces may damage its filamentous network and deteriorate biosynthesis of IA consequently. ...
Article
Full-text available
The effects of the bioreactor conditions, in particular the mode and intensity of aeration and mixing were studied on itaconic acid (IA) fermentation efficiency by Aspergillus terreus strain from glucose substrate. IA was produced in batch system by systematically varying the oxygen content of the aeration gas (from 21 to 31.5 vol% O2) and the stirring rate (from 150 to 600 rpm). The data were analyzed kinetically to characterize the behavior of the process, and besides, the performances were evaluated comparatively with the literature. It turned out that the operation of the bioreactor with either the higher inlet O2 concentration (31.5 vol% O2) or faster stirring (600 rpm) could enhance biological IA generation the most, resulting in yield and volumetric productivity of 0.31 g IA/g glucose and 0.32 g IA/g glucose and 3.15 g IA/L day and 4.26 g IA/L day, respectively. Overall, the significance of fermentation settings was shown in this work regarding IA production catalyzed by A. terreus and notable advances could be realized by adjusting the aeration and stirring towards an optimal combination. Graphic abstract Open image in new window
... It is also known that the microbial physiology of filamentous fungal cells is significantly influenced by the DO concentration in suspended cultures, and it has been suggested that the critical DO concentration for fungal cells in culture should be greater than around 20% of the saturation DO value [45,46]. In this study, no effort was made to maintain the DO above 20% in order to investigate the effect of DO on enzyme production by the fungus T. reesei MUM 97.53. ...
Article
Full-text available
Enzymatic hydrolysis accounts for 20% of the total cost in the conversion process of lignocellulosic biomass into bioethanol. Therefore, production of biomass-degrading enzymes by using lignocellulosic residue as a fermentation substrate may be an alternative to decrease the production costs. In this study, corncob (CC) has been pretreated by liquid hot water (LHW) at 200 °C for 30 min and used as inducer source for production of biomass-degrading enzymes by Trichoderma reesei MUM 97.53. The pretreatment was used to increase the cellulose content and the accessibility to lignocellulosic material. Although the filamentous fungus secreted a broad range of cellulolytic and hemicellulolytic enzymes when grown on untreated CC, higher enzyme productions were obtained when cultured on LHW-pretreated CC in a 2-L stirred tank bioreactor (STB). Besides, the effects of aeration (2 and 4 vvm) and agitation (150 and 250 rpm) rates on enzyme production were studied by submerged fermentation in a batch STB and correlated with the volumetric oxygen transfer coefficient (kLa). Maximal cellulase, xylanase, and β-xylosidase productions were found at 150 rpm and 4 vvm, while the highest β-glucosidase levels were obtained at 150 rpm and 2 vvm, that corresponded to kLa values of 32.50 h−1 and 16.41 h−1, respectively. At higher agitation, a lower enzymatic production was observed probably due to the high shear stress in the fungal hyphae.